Design of pulse and trigger simulator electronic board for AMS experiment

The Alpha Magnetic Spectrometer (AMS) is a space borne particle physics experiment designed to search for and measure, with a much greater sensitivity than heretofore possible, various unusual types of matter. The apparent absence of antimatter (antihelium, anticarbon, etc.) in the universe is one of the great puzzles in particle physics. Theories (based on CP-violation, Baryon-number-violation, the Standard Model, and Grand Unification) which predict either the existence of antimatter in segregated domains or the total absence of antimatter are highly speculative. These theories have no foundation in experimental data. The AMS experiment has been approved and is under way in order to search for antimatter in cosmic radiation with a sensitivity of 10/sup 3/ to 10/sup 5/ times better than existing measurements, sufficiently sensitive to provide data needed to address these particle physics issues. AMS has two missions in space. The first mission was a ten day flight on the space shuttle Discovery. This shuttle mission has been completed with about 100 hours of dedicated data taking time, in June 1998, on the NASA STS-91 mission. The analysis of the data taken in space is currently in progress. We have designed and implemented the Signal and Trigger Simulator (SiTSi) board which allows the Time of Flight system to be tested and calibrated in stand-alone mode, and integrated with the AMS for the shuttle mission STS-91.